The study of gene expression and its control in eucaryotic cells has required the use of model systems due to the complexity of the eucaryotic cell. One of the most rewarding of such model systems has been the infection of human cells by human adenoviruses. This proposal is concerned with advancing our knowledge of the molecular biology of adenovirus with respect to a very interesting and little understood phenomenon recently observed in eucaryotic cells. That phenomenon is the split nature of eucaryotic genes. Adenovirus was one of the first systems for which such split gene structure and their spliced RNAs were demonstrated and presents a unique model system with which to study their expression. The overall aim of the proposed research is to establish the first paradymes of the transcription of eucaryotic split genes so that they may be applied to more general systems. My proposed research is designed to study viral late gene transcription with an emphasis on the production of spliced RNA.